Bathing appliances in the nature of spas, or so-called hot tubs, have become commercially successful. These spas are typically constructed as a molded shell to form a water containment, with seats, footwells, platforms for reclining, and the like molded into the shape of the shell. The shell is usually molded from plastic or fiberglass or a composite thereof. A pump or pumps usually placed in a chamber under the shell draw water from the water containment and reinject the water into the containment through a variety of nozzles, hydrotherapy jets, and the like. The jets are usually mounted in the shell under the water line, and are designed to provide a comforting or therapeutic effect to a person in the spa. The jets are usually mounted by making a hole in the shell, and fixing the jet in the hole by a use of seals, adhesives, welding compounds, or a combination thereof. Water supply lines from the pumps to the jets are usually flexible tubing or rigid PVC tubing. After the jets and tubing are in place, an expandable foaming polymeric material is blown into the empty spaces to provide thermal and sound insulation. This construction system has been used widely and successfully, and is currently almost universally used.
However, there are continuing problems in the prevention of leaks in these spas and in the repair of leaks. Jets are almost always mounted in a hole under the water-line of the shell, which presents the possibility of leaks around the jets. Plastic welding, sealants and various sealing systems have been used to prevent leaks, but with the relatively large number of jets being used in present construction, the development of leaks at or around the jets is a frequent occurrence. Leaks also occur in the water supply lines, at welded joints where they are joined to the jets, and in other fittings. In addition, poor workmanship and defects in the materials cause leaks. Over time, the thrust or line pressure and the variation in line pressure from the pumps being turned on and off, tend to flex joints and seals and eventually open them up to form leaks. This has become a particular problem in the plumbing system used currently for most new spas, where flexible tubing lines to the various jets are stretched over barbed fittings on a manifold. The fluctuating pressure over a period of time tends to expand the flexible tubing and loosen the seal at the barbs. In addition, the clear vinyl tubing frequently used for supply lines between the jets and the manifolds frequently deteriorates from reaction with components in the water, such as chlorine or ozone oxidants, or other water additives. This greatly aggravates the problems as these lines are usually buried in foam.
The second serious problem is the detection of the source of leaks and their repair. The tubing, plumbing, jet and manifold connections, and the like, are usually buried in the foam covering the underside of the shell. To access a leak, the spa must be emptied and turned on its side. The foam must then be dug out to access the leaking jets or connections. Since, the leak cannot be directly observed it must often be diagnosed by tracing the track of the leak through wet foam (sometimes by using a dye in the water), or by observing other signs of leakage or water damage. This is an imprecise process and can result in unnecessary misdiagnosed or precautionary repairs. Furthermore, even with the foam removed, the complexity of the jet and plumbing designs creates a "spaghetti bowl" of tubing which can render access to a particular jet or joint nearly impossible.
Once the leak site is determined, removal and replacement of the defective component often involves cutting out and removing the welds or seals of the part with the shell, and then replacing them with new parts. For example, to replace a jet, the old jet must often be cut out and removed from the water connection. The old sealant materials must be scraped off from surfaces around the hole in the shell. The new jet, must then be resealed to the shell hole, and the water connections resealed rewelded, or spliced into place.
This labor intensive procedure not only occurs for leak repair, but is also often required for replacing a defective non-leaking jet, or for replacing a jet with a different type of jet. Thus, a user is essentially precluded from upgrading his spa with new jets of a different type or a different size, since jet replacement is usually difficult or impossible.
When a leak does occur, it is important that the leak be repaired soon, for a leak can lead to further damage of spa components, and to the surroundings of the spa. In addition, when leaking water soaks into and saturates the insulating foam, the water substantially reduces the R-value of the foam. This can substantially increase the energy costs for heating the water.
In summary, the present systems are prone to leaks at nearly inaccessible, difficult to reach locations. The leaks are often difficult to diagnose, and the repair is costly and labor intensive. The difficultly in replacing jets precludes any real flexibility on the part of the spa owner in adapting the spa and its jet designs and types to his own individual interests.